An acoustic measuring apparatus can be used for determining a level of a fluid surface in a fluid container. A sound transducer of the acoustic measuring apparatus can operate both as sound generator and as sound receiver. For the purposes of determining the level of the fluid surface in the fluid container, it is possible to emit sound pulses into the fluid to be measured by means of the sound transducer. The sound pulses can be reflected by an interface of the fluid to a further medium. From the time-of-flight of the sound pulses, it is possible to draw conclusions about the level of the fluid surface in the fluid container.